Chain wrench.



G. M. MITCHELL, SR.

CHAIN WRENCH.

APPLICATION FILED AUG. 18. 1915.

Patented May 9,1916.

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X) ATTORNEY will m'IEilmu WITNESS UNITED STATES PATENT OFFICE.

GEORGE M. MITCHELL, SR 0F PATERSON, NEW JERSEY.

CHAIN WRENCH.

T 0, all whom it may concern Be it known thatI, GEORGE M. MITCHELL, Sr., a citizen of the United States, residing at Paterson, in the county of Passaic and State of New Jersey, have invented certain new and useful Improvements in Chain Wrenches, of which the following is a specification.

This invention relates particularly to that class of chain wrenches in which the ends of the chain are attached to the handle or lever of the wrench at different distances from the hand-end thereof and the contraction and relaxation of the chain to cause it to grip or release the pipe or the like are effected by movement of the handle on a fulcrum axis parallel with the axis of the pipe or the like.

According to this invention, that end portion of the handle orlever which is the nearer to the pipe (hereinafter termed its grip end) constitutes a pivoted head of the handle or lever and the chain is attached on the one hand to said head and on the other to the body part of the lever. In the preferred construction, the. chain rests upon the head at the side thereof facing away from its piv.

0t and said head has means to interlock with the chain at different stages therein thus to afford a rough adjustment of the wrench to the pipe preliminary to effecting the grip on the latter.

The principal object of the invention is to provide a chain wrench whereby a powerful grip may be attained, and yet the pressure around the pipe kept as uniform as possible, thus to prevent crushing the pipe, and whereby the wrench may be employed in many applications where the ordinary chain wrenches would be incapable of effective use.

In the accompanying drawing, Figure 1 is a side elevation of the improved wrench, a pipe gripped thereby appearing in section; Fig. 2 shows what is seen in Fig. 1 when viewed in the direction of the dotted arrow in said figure; Fig. 3 is a view like Fig. 2, excepting that the pipe, the movable head of the lever and a part of the chain are omitted; Fig. 4 is a plan view of the device; Fig. 5 is a sectional View of the said head; and, Fig. 6 shows one of the toothed links in the chain.

The handle or lever includes a body part a which at one end is forked, as at b, the forked portion being traversed by a pin 0 extending at right angles to the plane of the slot d of the fork and having its ends upset or riveted to retain it in place. Said handle Specification of Letters Patent.

Patented May 9, 1916.

Application filed August 18, 1915. Serial No. 46,049.

also includes the movable head 6 which is pivoted on the pin 0, its portion 6 closely fitting the slot (Z and its portion 6 being widened to about the thickness of the body part a of the handle and formed with a slot f open away from the pin 0 and extending transversely thereto. At both sides of the slot f the portion 6 of the head 6 is formed with one or more recesses 9 also open away from the pin 0, the same being inclined upwardly to the left in that elevation of the Wrench shown by Fig. 1. At a point just short of the forked end I) of the body part a the latter is penetrated by a pin it parallel with pin 0. On each end of this pin is pivoted one end of each of a pair of links z, each of which is preferably spaced from the body part a of the handle by a washer j and is retained on the pin by riveting or upsetting the end thereof. To the other ends of the pair of links 71 is pivotally connected one end of a chain 7c. The said chain is generally of a well known type, consisting of single links is alternating with pairs of links k (the links in each pair of which flank the adjoining ends of two adjoining links 70) and pivot pins 70 penetrating and thus coupling together the links is and 70 however, in the present construction the ends of the pins k are somewhat extended beyond the outer sides of the links 70 and the links 14 are preferably toothed, as at is", so as to obtain an effective grip on the pipe as will be explained. It may be remarked that the length of the pins 70 is such that they may clear the links i on the free end of the chain being extended between the links 2' as shown in Figs. 1 and 2. Also, that if there is more than one pair of recesses g in the head 6, they are spaced to conform to the spacing of the pins 10 In operation, the handle of the lever is first placed in relation to the pipe A or other part to be turned more or less in the position shown in Fig. 1, whereupon the chain is passed around the pipe extending from the left side of the handle in the elevation of the wrench seen in Fig. 1, its free end being extended between the head 6 and the pipe and then between the links 2'; thereupon, those pins k which will register with the recesses g by the slack in the chain being taken up as far as possible are entered into said recesses. It will be understood that the teeth is of the chain should adjoin the pipe on the wrench having been applied thereto in the way above explained. On pressure now being applied to the handlein the direction of the arrow shown by full lines in Fig. 1, the'handle forces the pin h to the right and the pins 10 interlocked with the head e to the left, until the grip of the chain on the pipe becomes effective to turn the latter, whereupon the turning thereof of course follows. It may be remarked that the teeth is of the chain face oppositely to the direction to which the chain extends from the pin It, thus to obtain their contemplated action upon the pipe. Because the grip end of the handle includes a pivoted head to which the chain is on the one hand attached, in the operation involved in effecting the grip on the pipe the efiect is to direct the part of the chain directly engaged with said head around the pipe more or less and not off at a tangent. Further, the gripping operation is one characterized by a gradual and uniform constriction of the embracing portion of the chain and not by pressure on the pipe which is appreciably more at one point than it is at another; thus, the strain on the pipe being equalized almost continuously around it, the probability of crushing the pipe is greatly reduced.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a chain wrench, the combination of a lever including a body part and a head pivoted to one end of the body part, and a chain to embrace the Part to be gripped and turned connected to the head and body part on relatively opposite sides of the pivot between the head and body part, the chain extending across the side of the head facing away from said body part.

2. In a chain wrench, the combination of a lever including a body part and a head pivoted to one end of the body part, and a chain to embrace the part to be gripped and turned connected to the head and body part on relatively opposite sides of the pivot between the head and body part, the chain extending across the side of the head facing away from said body part and being separably interlocked therewith.

3. In a chain wrench, the combination of a lever including a body part and a head pivoted to one end of the body part, and a chain to embrace the part to be gripped and turned connected to the head and body part onrelatively opposite sides of the pivot between the head and body part, the chain extending across the side of the head facing away from said body part, and being separably interlocked therewith, said head having at said side a groove receiving the chain.

In testimony whereof I affix my signature.

GEORGE M. MITCHELL, SR.

Copies of this patent may be obtained for five cents each; by addressing the Commissioner of Patents,

Washington. D, 0. 

